1. Technical Field
The invention relates generally to communication systems; and, more particularly, it relates to signal processing within a communication system's receiver that receives multiple signals.
2. Related Art
It is known that many communication systems transmit digital data through imperfect communication channels. These symbols may undergo some undesirable corruption due to the imperfection of the communication channel. One effort to try to avoid such situations is focused on performing forward error correction (FEC) coding. However, there is typically some difficulty in extracting the information contained within these symbols after they have been undesirably altered within the communication channel. There exist some methods that seek to curb the effect that the communication channel has had on the data; one such method includes employing using Decision Feedback Equalizers (DFEs). However, even after the incoming signal has been equalized, the extraction of the data, that has undergone some alteration due to the channel effects, is still a probabilistic determination. Many communication systems seek to estimate the actual channel response of a communication channel. Of the many deficiencies that may be introduced in doing this, one major problem is the undesirable introduction of noise into both the estimate of the channel response as well as the estimate of the channel noise within the communication system.
The VOFDM standard defines the physical layer and additional layers in which a plurality, e.g., up to 1,024 separate carriers (tones) carry either data (data tones) or pilot signals (pilot tones). The 1,024 tones are separated in frequency such that they are orthogonal to one another. One current implementation of a wireless communication system employs vector orthogonal frequency division multiplexing (VOFDM); the VOFDM standard also defines a receiver implementation having two antennae. These two antennae each operate on their own respective receive path, and those different receive paths are then combined into a single signal for subsequent signal processing. The signals received via each of the two antennae are combined using a combining methodology to perform beam forming. The beam forming involves taking these two signals and perform channel combining, combining of these two different receive paths. The calculations that are required to perform this channel combining are typically very computationally intensive in the prior art approaches.
More specifically, correlation matrixes are required for combining the input data for the two antennae according to the VOFDM specification. These correlation matrices are 2×2 for the typical 2-antenna case. The operations provided for in the VOFDM standard require significant matrix operations to combine the data from the multiple antennas using the correlation matrices. To perform these complex operations, a significant amount of computational processing resources must be employed in the prior art approaches. Such significant matrix operations require a large number of mathematical operations. In prior art approaches, these significant processing resources must simply be dedicated and provisioned. These computational intensive equations must necessarily be carried out with significant precision in general, to avoid numerical instability and quantization noise impacting the results. The provisioning of these intensive computational resources inherently draws away from other resources within the receiver system.
Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art through comparison of such systems with the invention as set forth in the remainder of the present application with reference to the drawings.